1. Field of the Invention
The present invention relates to a dishwashing machine the washing tub of which is opened at the top for entry or takeout of tableware and is provided at its upper portion with a wash nozzle arm.
2. Description of the Prior Art
Such a dishwashing machine as described above is disclosed, for example, in Japanese Utility Model Laid-open Publications Nos. 1-128750 and 1-138257. In a dishwashing machine disclosed in Japanese Utility Model Laid-open Publication No. 1-128750, tile upper opening of the washing tub is closed by a door which is provided with a wash nozzle arm. Since the door is mounted at its rear end on a rear end of the upper opening to be opened upwardly, it is required to provide an upper space for upward movement of the door. As a result, the installment place of the dishwashing machine is limited. In addition, when the door is opened, a handle mounted on the front end of the door is positioned behind the door, resulting in difficulty of operation of the door.
In a dishwashing machine disclosed in Japanese Utility Model Laid-open Publication 1-138257, the upper opening of the washing tub is closed by a door in the form of a flexible shutter. Since a frictional resistance at the contact portion of the shutter with its guide rails is inevitably increased, smooth movement of the shutter may not be expected. Since in the prior art of the dishwashing machines, the upper wash nozzle arm is arranged at one side of the upper opening to permit entry of tableware, the washing extent of the upper wash nozzle arm is limited, and uniform washing of the tableware may not be effected.